(i) Field of the Invention
The present invention is an asthma drug inhaler with a whistle, which makes a sound so as to allow a patient to check whether or not the drug inhalation can be appropriately accomplished without fault when the patient of the bronchial asthma inhales the finely powdered drug for asthma medication.
(ii) Description of the Related Art
Conventionally, as the antiasthmatic drug, the internal medicine had been mainly used. However, the asthma drug inhaler of the aerosol type was developed thereafter, with which the liquid medicine is misted by the use of a small tank charged with chlorofluorocarbon, and the patient inhales the misted medicine.
As is well known, the chlorofluorocarbon is the cause of the environmental destruction, and also, there is the concern over the effect on the human body. Therefore, the drug used in such a manner that the patient him/herself inhales the finely powdered drug has been increasingly brought into the mainstream. FIGS. 7 to 9 are the diagrams illustrating an example of the inhaler used in the manner that the drug is taken by the inhalation of the patient him/herself.
FIG. 7 is a front view of the conventional inhaler, FIG. 8 is a right side view of the conventional inhaler, and FIG. 9 is a plan view of the conventional inhaler. As shown in FIGS. 7 to 9, an asthma drug inhaler 9 is composed of a main body 9a, a disk cover 9b, a mouthpiece 10, a rotadisk 11 in which the finely powdered drug is individually packaged, and a small chamber 12.
As shown in FIGS. 7 to 9, small openings 10a and 10a are provided on both sides of the mouthpiece 10. The small openings 10a and 10a are used for taking air at the time of the inhalation.
More specifically, the small openings 10a are formed to correct the difference between the lung capacity in the inhalation and the air flow rate in the delivery passage of the finely powdered drug so as to prevent the breathing difficulty when taking air. If the small openings 10a are not provided, the patient will have the feeling of smothering when taking air.
The disk cover 9b is attached to the surface of the main body 9a, and a needle portion 9c is provided on the center of the upper part of the disk cover 9b. The needle portion 9c is used to open a hole 11a for the inhalation in the rotadisk 11 in which the drug is individually packaged. The reference numeral 9d denotes a semicircular protrusion.
When inhaling the drug with using the inhaler 9, by lifting the disk cover 9b immediately before its use, the needle portion 9c is stuck into a corresponding position of the rotadisk 11, in which the finely powdered drug is individually packaged. In this manner, the hole 11a is opened.
When the patient inhales the air through the mouthpiece 10 after opening the hole 11a, the drug flows into the small chamber 12 from the inside of the rotadisk 11 together with the air. The drug flown into the small chamber 12 and once dispersed therein is further dispersed after passing through a lattice 13 and delivered into the oral cavity through the mouthpiece 10.
In addition to the asthma drug inhaler 9 shown in FIGS. 7 to 9, there are several types of the inhaler having the structure that the finely powdered drug is inhaled by the patient him/herself. However, almost all of them have in common that the small openings for air intake are provided in the mouthpiece.
FIGS. 15 and 16 illustrate another conventionally used asthma drug inhaler 20, which is different from the asthma drug inhaler 9 shown in FIGS. 7 to 9. The asthma drug inhaler 20 of this example is formed of a cylindrical main body 21 and a mouthpiece 20a attached thereto.
In the asthma drug inhaler 20, four air-intake apertures 21c are provided in the upper part of the outer peripheral surface of a tube body 21a of the cylindrical main body 21, and an air hole 21e is provided in an engaging portion 21f attached to the lower part of the tube body 21a. An inhaled drug tube 21b, a scale 21d, and a drug reservoir tube 21g are provided inside the tube body 21a, and a partition lid 21h is attached to the upper part of the tube body 21a. The mouthpiece 20a is attached to the partition lid 21h. 
In the case where the patient inhales the asthma drug by the use of the asthma drug inhaler 20 by him/herself, when the patient inhales the air after holding an upper part 20b of the mouthpiece 20a in the mouth, the air flown in through the air hole 21e winds up the drug in the inhaled drug tube 21b and flows into the mouthpiece 20a through a drug inlet 20d of the mouthpiece 20a to generate the spiral flow in a spiral-shaped groove 20c, by which the finely powdered drug is dispersed and delivered into the oral cavity.
At this time, air is taken through the air-intake apertures 21c to correct the difference between the lung capacity in the inhalation and the air flow rate in the delivery passage of the finely powdered drug so as to prevent the breathing difficulty when taking air.
As described above, the conventionally used asthma drug inhalers can be largely classified into the two types as follows, that is, the type as shown in FIGS. 7 and 9, in which air is taken through the small openings provided in the mouthpiece, more specifically, air is taken from the lower stream of the air passage, and the type as shown in FIGS. 15 and 16, in which air is taken from the lower part and the upper part of the main body located below the mouthpiece, more specifically, air is taken from the upper stream of the air passage.